Door control linkage



N v- 1965 R. J. LYNN ETAL DOOR CONTROL LINKAGE Filed Dec. '3, 1965 5 Sheets-Sheet 1 INVENTORS ROBERT J. LYNN CLARENCE L. WANLUND GUS H. TRESLO BY hmlll-ln 7419 ATTORNEY Nov. 23, 1965 R. J. LYNN ETAL DOOR CONTROL LINKAGE 3 Sheets-Sheet 2 Filed Dec. 3, 1965 Nov. 23, 1965 R. J. LYNN ETAL 3,219,334

DOOR CONTROL LINKAGE United States Patent Delaware Filed Dec. 3, 1963, Ser. No. 327,664 (Jlaims. (Cl. 268-49) This invention relates in general to an apparatus for converting constant speed circular motion into one harmonic in nature, and more particularly to a linkage unit having a constant speed circular motion input and a rectilinear variable speed output, and still more particularly to a door control linkage for sliding doors between open and closed positions wherein the speed of the door between open and closed positions is gradually increased from zero to maximum and gradually decreased to zero.

The present invention may be more particularly referred to as a door operator for use in controlling the opening and closing of doors on railway passenger cars, wherein it is desired to accomplish the opening and closing operation quickly, efficiently and With regard of passenger safety. Accordingly, the speed of door movement, including acceleration and deceleration is of prime importance. Most of the door operators in use today are primarily electrical in nature, that is, they do not rely on mechanical control. For example, door speed, acceleration and deceleration are regulated by the positioning of cam switches which complete circuits through resistances to control motor action, wherein the motor drives through a straight gear reduction unit to an output drive arm. Thus, heretofore, a change in motor speed was essential, and was electrically controlled.

It is therefore an object of the present invention to provide a door operator that will obviate the above difliculties, and which involves primarily mechanical control.

Another object of this invention resides in the provission of apparatus for converting a constant speed circular motion to one harmonic in nature.

Still another object of this invention is in the provision of a door linkage unit driven by a constant speed circular motion to supply a motion to a door harmonic in nature such that the speed of the door is gradually increased from zero to maximum and then gradually decreased to zero during an opening and closing cyle.

A further object of this invention is to provide a door operator that is inherently self-locking when driving the door to a closed position.

Still another object of this invention is to provide a door operator that is simple in construction, eflicient and economical to manufacture, and which is capable of being installed in a minimum amount of space, and which is powered by a constant speed motor.

A further object of this invention is in the provision of a door control linkage for application to handle one or more doors.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is an elevational view of one form of the present invention and shown as installed in a railway car for operating a pair of door leaves, and illustrating in solid lines the position of the parts when the doors are in open position and in dotted lines the position of the parts when the doors are in closed position;

FIG. 2 is a top plan view of the mechanism shown in FIG. 1;

FIG. 3 is an end elevational view of the mechanism shown in FIG. 1;

3,219,334 Patented Nov. 23, 1965 ice FIG. 4 is a side elevational view of the linkage as seen in FIG. 1, illustrating the parts in solid lines when the doors are in open position, and in dotted lines when the doors are in closed position, and also illustrating a plurality of plotted points of movement of the linkage in graphical nature to illustrate the relative speed of the door between open and closed positions; and

FIG. 5 is an elevational view of a modification of the invention and showing the parts in open, intermediate and closed positions.

Referring now to the drawings, and particularly to FIGS. 13, a preferred form of the present invention is illustrated in having a linkage unit generally indicated by the numeral 20 as installed along a side wall 21 of a railway vehicle to operate door leaves 22 and 23. It should be appreciated that most railway passenger cars, such as subway cars, are provided with door openings that have double leaves for closing and opening the openings, which leaves move in opposite directions. Thus, in such an installation, the door leaves 22 and 23 would serve to coact with half of a door opening along a side wall of a car.

While the present invention is illustrated as applied to a railway car in particular, it should be appreciated that other uses and purposes would be apparent to one skilled in the art, wherein the invention maybe applied to any sitnation where it is desired to convert constant rotary motion into rectilinear variable speed motion. And more particularly, the present invention involves the application of door operators for railway passenger cars, but application could also be made to other passenger vehicles, such as buses, or the like.

The linkage unit 20, together with a constant speed reversible electric motor 24 and reduction gear unit 25, constitutes a door operator for handling of door leaves 22 and 23. While the motor 24 herein is referred to as being electrical, it should be appreciated that any type of motor may be applied to the present invention as long as constant speed and reversible characteristics are available. The motor 24 is connected to drive the reduction gear unit 25 having an output drive shaft 26, although it should be appreciated that the motor 24 may have its drive shaft directly connected to the linkage 20 rather than through a reduction gear unit if so desired. Thus, the drive shaft 26, producing constant speed circular or rotary motion, is connected to the door control linkage 20.

The motor 24 and reduction gear unit 25 are mounted on a bracket 27 that is secured between upstanding posts 28 and 29 which form a part of the structure of the railway vehicle. Thus, the drive shaft 26 rotates in a fixed location along the bracket 27.

The linkage unit 20 includes generally a double crank 30 secured to the drive shaft 26, first and second floating levers 31 and 32, and first and second cranks 33 and 34. The double crank 30 is Z-shaped, while the first and second floating levers 31 are U-shaped. Actually, the double crank 30 is constructed of a pair of identical aligned plates 30a and 301) as seen particularly in FIG. 2, and is pivotally connected at 35 to the first floating lever 31 and pivotally connected at 36 to the second floating lever 32. The other end of the first floating lever 31 is pivotally connected to a connecting rod 37 that connects to the door leaf 22, and the other end of the second floating lever 32 is pivotally connected to a connecting rod 38 that is, in turn, connected to the door leaf 23. The first crank 33 is pivotally mounted at one end on a shaft 39 carried by the bracket 27 and at the other end pivotally connected at 40 to the first floating lever 31 intermediate its ends. Likewise. the second crank 34 is pivotally mounted at one end on a shaft 41 carried by the bracket 27 and pivotally mounted at the other end at 42 to the second floating lever 32 intermediate its ends. It may be noted that the pivot connections 40 and 42 are closer to the ends of the floating levers 31 and 32 that are connected to the connecting rods 37 and 38.

Some refer to the linkage unit as a four-bar linkage, although this linkage unit consists of actually three bars. The fourth bar is considered as being located between the two fixed centers such as 26 and 39 or 26 and 41, and since the fixed centers do not move, the fourth bar is not necessary. In other linkage of this type where these center would move, the fourth bar would be necessary.

The connecting rods 37 and 38 are preferably of the resiliently extendable type so that if the door leaves closed on an object, the rods would give and not cause injury to the object or to the linkage unit. Further, the connecting rods 37 and 38 are pivotally connected at one end to the respective floating levers 31 and 32 and pivotally connected at the other ends to the door leaves 22 and 23. In order to provide adjustment for door leaf travel and to compensate for variations in door openings, slots 43 and 44 are respectively provided in the ends of the floating levers 31 and 32 so that the respective ends of the connecting rods 37 and 38 may be adjustably secured to the floating levers 31 and 32.

Both FIGS. 1 and 4 show the parts of the linkage unit in solid lines as located when the door leaves are in open position, and in dotted lines when the door leaves are located in closed position. From the open position to the closed position, the double crank is rotated in a counterclockwise direction, and conversely, from a closed position to an open position, the double crank 3d is rotated in a clockwise direction.

Referring now particularly to FIG. 4, the relative points of movement of the pivot points 35, 36, 40 and 42 of the floating levers 31 and 32 are plotted and also shown on the chart which indicates the door travel of the leaves 22 and 23. The door travel chart of leaf 22 is generally designated by the numeral 22A, while the door travel chart of the leaf 23 is generally designated by the numeral 23A. As is seen, the trajectory points of the pivots 35 and 36 are equally spaced and spaced apart approximately 10 degrees to give a total travel for door movement of 120 degrees rotation of the shaft 26. However, the movement of the pivot points 40 and 42 is not constant and it is this movement that determines the speed of the door leaf travel, and referring to the charts 22A and 23A, it is seen that the linkage unit 20 accomplishes a gradual increase in velocity from zero to maximum and then a gradual decrease to Zero through one cycle of operation in either opening or closing of the door leaves. Therefore, it can easily be seen how the speed of the door varies and how door control is accomplished through the linkage unit 20 with a constant speed input on the shaft 26.

The segment of door travel between points 12 and 13 represents the over-center lock inherent in the linkage unit. A fixed mechanical stop 45 is positioned to stop movement of the double crank 30 after the linkage unit is in the over-center lock position. Should an attempt be now made to open the door leaves 22 or 23, a force would be applied against the drive crank 30 to rotate it against the stop 45, and thereby prevent further movement of either the door or the linkage. However, once the double crank 30 and pivot 36 is beyond the point 12 in the direction of point 13, the double drive crank 30 would always move toward point 13 upon pressure from the door leaves. However, in any other segment of the drive below point 12, the door could easily be pushed open by hand. In this regard, it is appreciated that an emergency release handle 2601 may be provided on the motor drive shaft to permit manual movement of the motor shaft so that the double crank 30 is closer to point 11 to release the over-center lock and enable the door leaves to be opened easily by pushing.

Because of the constant speed of the double crank 30 as illustrated by the point to point distance of pivot points 35 and 36, the dash length or distance between the points plotted in the charts 22A and 23A (door travel) divided by the time required for the double crank 30 to rotate from point to point gives the average velocity of a door leaf along the trajectory at that point.

Changing of the actual link lengths while maintaining the link ratios constant does not alter the motion characteristics of the linkage, although it does introduce a scale change. Thus, if a linkage is designed twice the size of that shown, the trajectory between two given points will be twice as large but unchanged in shape. The lengths vary directly with the change in scale. However, revolving the linkage in one direction or the other about the double drive crank center with respect to the horizontal, or changing the degrees of rotation of the double drive crank will alter the linkage characteristics greatly.

The linkage drive motor 24 is preferably compound wound for speed, stability and regulation. Positive action is applied to the door leaves by the linkage unit, and this action cannot change as long as the motor speed is constant. Thus, the linkage unit imparts a sine-curve type movement to door leaves with a constant speed drive. Moreover, the linkage provides over-center locking when the doors are closed, as well as a gradual start, high speed center travel, and gradual slow-down to final door position.

FIG. 3 illustrates the compactness of the door linkage arrangement in showing its relationship in a wall structure to a seat 46 mounted within a car.

Referring now to FIG. 5, an embodiment of the invention is shown which differs slightly in constructional features, but is primarily applicable to handle a single door leaf. However the general principles of the invention are maintained in the embodiment of FIG. 5, as would be also true if the double crank 30 was only a single crank and was connected only to a single floating lever and crank.

The embodiment of FIG. 5 includes a drive crank 47 fixed to a drive shaft 48 of a power supply. One end of the drive crank 47 is fixed to the power shaft 48, while the other end is pivotally connected at 49 to a floating lever 50. The floating lever 50 is intermediately connected to a driven crank 51 at 52, while the outer end 53 is adapted to be connected to a door leaf. The crank 51 is also pivotally mounted on a fixed shaft 54. When the door leaf is in fully open position, the parts are positioned as those indicated by the numerals 47a, 50a and 51a, in partially closed position as indicated by the numerals 47b, 50b and 51b, and in fully closed position as indicated by those numerals 47c, 50c and 510. The points of movement and a door chart are also illustrated in FIG. 5. As heretofore explained in connection with the embodiment of FIGS. 1-4, the operation of the embodiment of FIG. 5 will be the same, although it is applicable Where only a single door leaf is involved.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. In combination with a slidably supported member, apparatus for driving said member between first and second positions, said apparatus comprising a constant speed reversible motor, a drive shaft driven by said motor in one direction to drive said member to said first position and in the opposite direction to drive said member to said second position, a linkage imparting a variable speed to said member such that the speed thereof between said positions is gradually increased from zero to a maximum and then gradually decreased to zero, said linkage including a first crank mounted on said shaft, means engageable by said first crank to stop same when said member reaches said first position, a floating lever pivotally connected at one end to said first crank and at the other end to said slidable member, and a second crank pivotally mounted at one end to a fixed shaft and at the other end to said floating lever intermediate the ends thereof.

2. In combination with a pair of members slidable in opposite directions, apparatus for driving said members between first and second positions, said apparatus comprising a constant speed reversible motor, a drive shaft driven by said motor in one direction to drive said members to said first positions and in the opposite direction to drive said members to said second positions, a linkage imparting a variable speed to said members such that the speed thereof between said positions is gradually increased from zero to a maximum and then gradually decreased to zero, said linkage including a double crank mounted at its center on said shaft, means engaged by said double crank to stop same when said members reach said first positions, a first floating lever pivotally connected at one end to one end of said double crank and at the other end to one of said slidable members, a second floating lever pivotally connected at one end to the other end of said double crank and at the other end to the other of said slidable members, a first single crank pivotally mounted at one end to a first fixed shaft and at the other end to said first floating lever intermediate its ends, and a second single crank pivotally mounted at one end to a second fixed shaft and at the other end to said second floating lever intermediate its ends.

3. The combination as defined in claim 2, wherein said double crank is Z-shaped and each floating lever is U-shaped.

4. In combination with a sliding door slidable in opposite directions between open and closed positions, and a door operator having an output shaft supplying a constant speed circular motion in one direction to slide the door to open position and in the opposite direction to slide the door to closed position, a door control linkage converting said circular motion of said shaft to one harmonic in nature on said door when opening and closing same, said control linkage comprising, a first crank mounted on said output shaft, means engageable by said first crank to stop same when said door reaches open position, a floating lever pivotally connected at one end to said first crank and at the other end to said door, and a second crank pivotally mounted at one end to a fixed shaft and at the other end to said floating lever intermediate the ends thereof but closer to the end connecting to said door.

5. The combination as defined in claim 4, and an over center lock in said linkage operable when said door is in closed position.

6. In combination with a pair of doors slidable in opposite directions between open and closed positions and a door operator having an output shaft supplying a constant speed circular motion in one direction to slide the doors in one direction and in the opposite direction to slide the doors in the opposite direction, a door control linkage converting said circular motion of said shaft to one harmonic in nature on said doors when opening and closing same, said linkage comprising, a double crank mounted at its center on said shaft, means engageable by said double crank to stop same when said doors reach open position, a floating lever pivotally connected at one end to one end of said double crank and at the other end to one of said doors, a second floating lever pivotally connected at one end to the other end of said double crank and at the other end to the other of said doors, a first single crank pivotally mounted at one end to a first fixed shaft and at the other end to said first floating lever intermediate its ends, and a second single crank pivotally mounted at one end to a second fixed shaft and at the other end to said second floating lever intermediate its ends.

7. The combination as defined in claim 6, and an over center lock in said linkage operable when said doors are in one of said positions.

8. In combination with a pair of doors slidable in opposite directions, apparatus for driving said doors between first and second positions, said apparatus comprising, a constant speed reversible motor, a drive shaft driven by said motor in one direction to slide said doors to said first positions and in the opposite direction to slide said doors to said second positions, a linkage im parting a variable speed to said doors such that the speed thereof between said positions is gradually increased from zero to maximum and gradually decreased to Zero, said linkage including a double crank mounted at its center on said shaft, means engageable by said double crank to stop same when said doors reach said first position, a floating lever pivotally connected at one end to one end of said double crank and at the other end to one of said doors, a second floating lever pivotally connected at one end to the other end of said double crank and at the other end to the other of said doors, a first single crank pivotally mounted at one end to a first fixed shaft and at the other end to said first floating lever intermediate its ends, and a second single crank pivotally mounted at one end to a second fixed shaft and at the other end to said second floating lever intermediate its ends.

9. The combination as defined in claim 8, wherein said double crank is Z-shaped and said floating levers are U-shaped.

10. The combination as defined in claim 9, and an over center lock in said linkage operable when said door is in one of said positions.

References Cited by the Examiner UNITED STATES PATENTS 1,964,900 7/1934 Alt 7445 2,432,293 12/1947 Di Giovanni 26853 X 2,912,814 11/1959 Witt et a1 7444 X 2,924,106 2/1960 Bohm et al 7444 3,134,266 5/1964 Wallace 7444 OTHER REFERENCES Aronson: Machine Design, vol. 32, No. 23, 1960 (pp. -196).

HARRISON R. MOSELEY, Primary Examiner. 

1. IN COMBINATION WITH A SLIDABLY SUPPORTED MEMBER, APPARATUS FOR DRIVING SAID MEMBER BETWEEN FIRST AND SECOND POSITIONS, SAID APPARATUS COMPRISING A CONSTANT SPEED REVERSIBLE MOTOR, A DRIVE SHAFT DRIVEN BY SAID MOTOR IN ONE DIRECTION TO DRIVE SAID MEMBER TO SAID FIRST POSITION AND IN THE OPPOSITE DIRECTION TO DRIVE SAID MEMBER TO SAID SECOND POSITION, A LINKAGE IMPARTING A VARIABLE SPEED TO SAID MEMBER SUCH THAT THE SPEED THEREOF BETWEEN SAID POSITIONS IS GRADUALLY INCREASED FROM ZERO TO A MAXIMUM AND THEN GRADUALLY DECREASED TO ZERO, SAID LINKAGE INCLUDING A FIRST CRANK MOUNTED ON SAID SHAFT, MEANS ENGAGEABLE BY SAID FIRST CRANK TO STOP SAME WHEN SAID MEMBER REACHES SAID FIRST POSITION, A FLOATING LEVER PIVOTALLY CONNECTED AT ONE END TO SAID FIRST CRANK AND AT THE OTHER END TO SAID SLIDABLE MEMBER, AND A SECOND CRANK PIVOTALLY MOUNTED AT ONE END TO A FIXED SHAFT AND AT THE OTHER END TO SAID FLOATING LEVER INTERMEDIATE THE ENDS THEREOF. 